crypto/scompress.c

   1 /*
   2  * Synchronous Compression operations
   3  *
   4  * Copyright 2015 LG Electronics Inc.
   5  * Copyright (c) 2016, Intel Corporation
   6  * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20 #include <linux/crypto.h>
  21 #include <linux/compiler.h>
  22 #include <linux/vmalloc.h>
  23 #include <crypto/algapi.h>
  24 #include <linux/cryptouser.h>
  25 #include <net/netlink.h>
  26 #include <linux/scatterlist.h>
  27 #include <crypto/scatterwalk.h>
  28 #include <crypto/internal/acompress.h>
  29 #include <crypto/internal/scompress.h>
  30 #include "internal.h"
  31
  32 static const struct crypto_type crypto_scomp_type;
  33 static void * __percpu *scomp_src_scratches;
  34 static void * __percpu *scomp_dst_scratches;
  35 static int scomp_scratch_users;
  36 static DEFINE_MUTEX(scomp_lock);
  37
  38 #ifdef CONFIG_NET
  39 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  40 {
  41         struct crypto_report_comp rscomp;
  42
  43         strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
  44
  45         if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  46                     sizeof(struct crypto_report_comp), &rscomp))
  47                 goto nla_put_failure;
  48         return 0;
  49
  50 nla_put_failure:
  51         return -EMSGSIZE;
  52 }
  53 #else
  54 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  55 {
  56         return -ENOSYS;
  57 }
  58 #endif
  59
  60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  61         __maybe_unused;
  62
  63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  64 {
  65         seq_puts(m, "type         : scomp\n");
  66 }
  67
  68 static void crypto_scomp_free_scratches(void * __percpu *scratches)
  69 {
  70         int i;
  71
  72         if (!scratches)
  73                 return;
  74
  75         for_each_possible_cpu(i)
  76                 vfree(*per_cpu_ptr(scratches, i));
  77
  78         free_percpu(scratches);
  79 }
  80
  81 static void * __percpu *crypto_scomp_alloc_scratches(void)
  82 {
  83         void * __percpu *scratches;
  84         int i;
  85
  86         scratches = alloc_percpu(void *);
  87         if (!scratches)
  88                 return NULL;
  89
  90         for_each_possible_cpu(i) {
  91                 void *scratch;
  92
  93                 scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  94                 if (!scratch)
  95                         goto error;
  96                 *per_cpu_ptr(scratches, i) = scratch;
  97         }
  98
  99         return scratches;
 100
 101 error:
 102         crypto_scomp_free_scratches(scratches);
 103         return NULL;
 104 }
 105
 106 static void crypto_scomp_free_all_scratches(void)
 107 {
 108         if (!--scomp_scratch_users) {
 109                 crypto_scomp_free_scratches(scomp_src_scratches);
 110                 crypto_scomp_free_scratches(scomp_dst_scratches);
 111                 scomp_src_scratches = NULL;
 112                 scomp_dst_scratches = NULL;
 113         }
 114 }
 115
 116 static int crypto_scomp_alloc_all_scratches(void)
 117 {
 118         if (!scomp_scratch_users++) {
 119                 scomp_src_scratches = crypto_scomp_alloc_scratches();
 120                 if (!scomp_src_scratches)
 121                         return -ENOMEM;
 122                 scomp_dst_scratches = crypto_scomp_alloc_scratches();
 123                 if (!scomp_dst_scratches) {
 124                         crypto_scomp_free_scratches(scomp_src_scratches);
 125                         scomp_src_scratches = NULL;
 126                         return -ENOMEM;
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
 133 {
 134         int ret;
 135
 136         mutex_lock(&scomp_lock);
 137         ret = crypto_scomp_alloc_all_scratches();
 138         mutex_unlock(&scomp_lock);
 139
 140         return ret;
 141 }
 142
 143 static void crypto_scomp_sg_free(struct scatterlist *sgl)
 144 {
 145         int i, n;
 146         struct page *page;
 147
 148         if (!sgl)
 149                 return;
 150
 151         n = sg_nents(sgl);
 152         for_each_sg(sgl, sgl, n, i) {
 153                 page = sg_page(sgl);
 154                 if (page)
 155                         __free_page(page);
 156         }
 157
 158         kfree(sgl);
 159 }
 160
 161 static struct scatterlist *crypto_scomp_sg_alloc(size_t size, gfp_t gfp)
 162 {
 163         struct scatterlist *sgl;
 164         struct page *page;
 165         int i, n;
 166
 167         n = ((size - 1) >> PAGE_SHIFT) + 1;
 168
 169         sgl = kmalloc_array(n, sizeof(struct scatterlist), gfp);
 170         if (!sgl)
 171                 return NULL;
 172
 173         sg_init_table(sgl, n);
 174
 175         for (i = 0; i < n; i++) {
 176                 page = alloc_page(gfp);
 177                 if (!page)
 178                         goto err;
 179                 sg_set_page(sgl + i, page, PAGE_SIZE, 0);
 180         }
 181
 182         return sgl;
 183
 184 err:
 185         sg_mark_end(sgl + i);
 186         crypto_scomp_sg_free(sgl);
 187         return NULL;
 188 }
 189
 190 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 191 {
 192         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 193         void **tfm_ctx = acomp_tfm_ctx(tfm);
 194         struct crypto_scomp *scomp = *tfm_ctx;
 195         void **ctx = acomp_request_ctx(req);
 196         const int cpu = get_cpu();
 197         u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 198         u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 199         int ret;
 200
 201         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
 202                 ret = -EINVAL;
 203                 goto out;
 204         }
 205
 206         if (req->dst && !req->dlen) {
 207                 ret = -EINVAL;
 208                 goto out;
 209         }
 210
 211         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 212                 req->dlen = SCOMP_SCRATCH_SIZE;
 213
 214         scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
 215         if (dir)
 216                 ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
 217                                             scratch_dst, &req->dlen, *ctx);
 218         else
 219                 ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
 220                                               scratch_dst, &req->dlen, *ctx);
 221         if (!ret) {
 222                 if (!req->dst) {
 223                         req->dst = crypto_scomp_sg_alloc(req->dlen, GFP_ATOMIC);
 224                         if (!req->dst)
 225                                 goto out;
 226                 }
 227                 scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
 228                                          1);
 229         }
 230 out:
 231         put_cpu();
 232         return ret;
 233 }
 234
 235 static int scomp_acomp_compress(struct acomp_req *req)
 236 {
 237         return scomp_acomp_comp_decomp(req, 1);
 238 }
 239
 240 static int scomp_acomp_decompress(struct acomp_req *req)
 241 {
 242         return scomp_acomp_comp_decomp(req, 0);
 243 }
 244
 245 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 246 {
 247         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 248
 249         crypto_free_scomp(*ctx);
 250
 251         mutex_lock(&scomp_lock);
 252         crypto_scomp_free_all_scratches();
 253         mutex_unlock(&scomp_lock);
 254 }
 255
 256 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 257 {
 258         struct crypto_alg *calg = tfm->__crt_alg;
 259         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 260         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 261         struct crypto_scomp *scomp;
 262
 263         if (!crypto_mod_get(calg))
 264                 return -EAGAIN;
 265
 266         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 267         if (IS_ERR(scomp)) {
 268                 crypto_mod_put(calg);
 269                 return PTR_ERR(scomp);
 270         }
 271
 272         *ctx = scomp;
 273         tfm->exit = crypto_exit_scomp_ops_async;
 274
 275         crt->compress = scomp_acomp_compress;
 276         crt->decompress = scomp_acomp_decompress;
 277         crt->dst_free = crypto_scomp_sg_free;
 278         crt->reqsize = sizeof(void *);
 279
 280         return 0;
 281 }
 282
 283 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 284 {
 285         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 286         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 287         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 288         struct crypto_scomp *scomp = *tfm_ctx;
 289         void *ctx;
 290
 291         ctx = crypto_scomp_alloc_ctx(scomp);
 292         if (IS_ERR(ctx)) {
 293                 kfree(req);
 294                 return NULL;
 295         }
 296
 297         *req->__ctx = ctx;
 298
 299         return req;
 300 }
 301
 302 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 303 {
 304         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 305         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 306         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 307         struct crypto_scomp *scomp = *tfm_ctx;
 308         void *ctx = *req->__ctx;
 309
 310         if (ctx)
 311                 crypto_scomp_free_ctx(scomp, ctx);
 312 }
 313
 314 static const struct crypto_type crypto_scomp_type = {
 315         .extsize = crypto_alg_extsize,
 316         .init_tfm = crypto_scomp_init_tfm,
 317 #ifdef CONFIG_PROC_FS
 318         .show = crypto_scomp_show,
 319 #endif
 320         .report = crypto_scomp_report,
 321         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 322         .maskset = CRYPTO_ALG_TYPE_MASK,
 323         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 324         .tfmsize = offsetof(struct crypto_scomp, base),
 325 };
 326
 327 int crypto_register_scomp(struct scomp_alg *alg)
 328 {
 329         struct crypto_alg *base = &alg->base;
 330
 331         base->cra_type = &crypto_scomp_type;
 332         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 333         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 334
 335         return crypto_register_alg(base);
 336 }
 337 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 338
 339 int crypto_unregister_scomp(struct scomp_alg *alg)
 340 {
 341         return crypto_unregister_alg(&alg->base);
 342 }
 343 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 344
 345 int crypto_register_scomps(struct scomp_alg *algs, int count)
 346 {
 347         int i, ret;
 348
 349         for (i = 0; i < count; i++) {
 350                 ret = crypto_register_scomp(&algs[i]);
 351                 if (ret)
 352                         goto err;
 353         }
 354
 355         return 0;
 356
 357 err:
 358         for (--i; i >= 0; --i)
 359                 crypto_unregister_scomp(&algs[i]);
 360
 361         return ret;
 362 }
 363 EXPORT_SYMBOL_GPL(crypto_register_scomps);
 364
 365 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
 366 {
 367         int i;
 368
 369         for (i = count - 1; i >= 0; --i)
 370                 crypto_unregister_scomp(&algs[i]);
 371 }
 372 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
 373
 374 MODULE_LICENSE("GPL");
 375 MODULE_DESCRIPTION("Synchronous compression type");